1. Submission doc.: IEEE 802.11-12/0834r0 Speed Frame Exchange Date: 2012-07-16 Slide 1 Authors: July 2012 Eric Wong, Broadcom NameAffiliationsAddressPhoneEmail Eric WongBroadcomSunnyvale, CA+1 408 922 6672ewong@broadcom.com Matthew FischerBroadcommfischer@broadcom.com Yongho SeokLG Electronics Jinsoo ChoiLG Electronics Jeongki KimLG Electronics Jin Sam KwakLG Electronics ChaoChun WangMediaTek James WangMediaTek Jianhan LiuMediaTek Vish PonnampalamMediaTek James YeeMediaTek Thomas PareMediaTek Kiran UlnMediaTek Huai-Rong Shao Samsung Chiu NgoSamsung Minyoung ParkIntel Tom TetzlaffIntel Emily QiIntel

2. Submission doc.: IEEE 802.11-12/0834r0 Slide 2Eric Wong, Broadcom July 2012 NameAffiliationsAddressPhoneEmail Yong LiuMarvell Hongyuan ZhangMarvell Sudhir SrinivasaMarvell Simone MerlinQualcomm Alfred AsterjadhiQualcomm Amin JafarianQualcomm Santosh AbrahamQualcomm Menzo WentinkQualcomm Hemanth SampathQualcomm VK JonesQualcomm George CalcevHuawei Osama Aboul MagdHuawei Young Hoon KwonHuawei Betty ZhaoHuawei David YangxunHuawei Bin ZhenHuawei Minho CheongETRI Jae Seung LeeETRI Hyoungjin KwonETRI Heejung YuETRI Jaewoo ParkETRI Sok-kyu LeeETRI Sun, Bo ZTE Lv, Kaiying ZTE Authors:

3. Submission doc.: IEEE 802.11-12/0834r0 Slide 3Eric Wong, Broadcom July 2012 Authors: NameAffiliationsAddressPhoneEmail Sayantan ChoudhuryNokia Taejoon KimNokia Klaus DopplerNokia Chittabrata GhoshNokia Esa TuomaalaNokia Ken MoriPanasonic Rojan ChitrakarPanasonic Shoukang ZhengI2R Haiguang WangI2R Wai Leong YeowI2R Zander LeiI2R Jaya ShankarI2R Anh Tuan HoangI2R Joseph Teo Chee MingI2R

4. Submission doc.: IEEE 802.11-12/0834r0 Outline Proposal in [1] permits a STA to send a PS-Poll at any time, and AP replies with either DATA or ACK (and More Data field set) Primarily use for downlink data retrieval by STA STA uses separate medium access for uplink data transmissions Inefficient because More frame transactions are needed per DATA frame Separate uplink and downlink access and contention Results in Longer STA wake times and higher power consumption This suggests a combined uplink and downlink medium access Propose an approach for speed frame exchange Slide 4Eric Wong, Broadcom July 2012

5. Submission doc.: IEEE 802.11-12/0834r0 Uplink or Downlink Data Indication Propose use of More Data field to indicate more UL Data Currently in 802.11-REVmb/D12 [4], it indicates more DL Data Buffered data at the AP for a STA in power save (in a DATA frame) AP has a pending transmissions, if an APSD-STA advertises support for More Data ACK (in an ACK frame) TDLS peer STA has pending transmissions More broadcast or multicast frames buffered at the AP (within a group- addressed DATA frame) Slide 5Eric Wong, Broadcom July 2012

6. Submission doc.: IEEE 802.11-12/0834r0 Station with no Uplink or Downlink Data Slide 6Eric Wong, Broadcom SIFS ProbeDelay AP ACK STA wakes from sleep, e.g. at a scheduled wake time MoreData=0 RspFrm=10 STA returns to sleep since last MoreData from AP is 0 PS-POLL STA Wake STA either misses Beacon, or chooses not to wake for Beacon. [1] July 2012

7. Submission doc.: IEEE 802.11-12/0834r0 Station with Downlink Data Only Slide 7Eric Wong, Broadcom ACK STA wakes from sleep, e.g. at a scheduled wake time STA returns to sleep since last MoreData from AP is 0 SIFS ProbeDelay AP PS-POLL STA Wake DATA SIFS AP readies DL DATA for transmission to STA that is scheduled to wake. [1] MoreData=0 RspFrm=00 MoreData=0 RspFrm=10 MoreData=? RspFrm=00 July 2012

8. Submission doc.: IEEE 802.11-12/0834r0 Station with Downlink Data Only Slide 8Eric Wong, Broadcom ACK SIFS STA wakes from sleep, e.g. at a unscheduled wake time STA returns to sleep since last MoreData from AP is 0 SIFS ProbeDelay AP PS-POLL STA Wake DATAACK SIFS MoreData=0 RspFrm=00 AP is unprepared for STA that is waking at an unscheduled time. AP sends DL ACK while it completes the retrieval of DL DATA from buffer space. [1] MoreData=1 RspFrm=11 Note, new value of Response Frame bits MoreData=0 RspFrm=10 July 2012

9. Submission doc.: IEEE 802.11-12/0834r0 Data Frame Indication DATA is another valid response frame type [3] Use Reserved (b11) to indicate in SIG Field the presence of a DATA frame following this current transmission Upon receipt, 3 rd party STAs will defer by (MAX_PPDU + 2*SIFS + PHY-RXSTARTDelay) Slide 9Eric Wong, Broadcom Response Frame (2-Bit)Frame Types 00ACK 01BA 10No Response 11Not ACK, CTS or BA July 2012

10. Submission doc.: IEEE 802.11-12/0834r0 Speed Frame Exchange Propose to combine medium access for uplink and downlink DATA If STA has buffered UL traffic, it starts frame exchange to the AP with UL DATA, instead of PS-POLL (supported by U-APSD) Instead of AP returning an ACK to STA, it can send the buffered DL DATA straightaway E.g. RDG=1 in UL Data Trigger frame Presence of next DATA frame indicates previous frame is successful I.e. implicit ACK, or combine BA with AMPDU Collisions are possible with the first UL DATA, but can be significantly reduced if STA is scheduled to wake by the AP [2] [5] Scheduling also allows AP to prepare DL DATA for a particular STA, reducing ACK-only DL response transmissions Slide 10Eric Wong, Broadcom July 2012

11. Submission doc.: IEEE 802.11-12/0834r0 Station with Uplink Data Only Slide 11Eric Wong, Broadcom SIFS ACK DATA STA wakes from sleep, e.g. at a scheduled wake time STA returns to sleep since last MoreData from AP is 0 SIFS ProbeDelay AP STA Wake ACK SIFS STA, with buffered UL traffic, starts transmission with UL DATA instead of PS-POLL. MoreData=0 RspFrm=00 DATA MoreData=1 RspFrm=00 MoreData=0 RspFrm=11 MoreData=0 RspFrm=10 MoreData is used to allow responder to correctly set Response Frame bits Because of MoreData in UL, responder knows that DATA is next July 2012

12. Submission doc.: IEEE 802.11-12/0834r0 Station with Uplink and Downlink Data Slide 12Eric Wong, Broadcom Both AP and STA have equal number of UL and DL DATA frames to be exchanged. Since AP is aware of STA wake time, it prepares DL DATA for STA. Note again, STA starts with UL DATA instead of PS-POLL. STA Wake SIFS D STA wakes from sleep, e.g. at a scheduled wake time STA returns to sleep since last MoreData from AP is 0 SIFS ProbeDelay AP SIFS D D MoreData=1 RspFrm=11 MoreData=0 RspFrm=00 MoreData=0 RspFrm=11 A SIFS MoreData=1 RspFrm=11 D MoreData=1 RspFrm=11 DD MoreData=1 RspFrm=00 MoreData=0 RspFrm=10 E.g. BA inside of AMPDU with DATA July 2012

13. Submission doc.: IEEE 802.11-12/0834r0 Station with Uplink and Downlink Data Slide 13Eric Wong, Broadcom STA returns to sleep since last MoreData from AP is 0 MoreData=0 RspFrm=11 SIFS A STA wakes from sleep, e.g. at a scheduled wake time AP and STA have unequal number of UL and DL DATA frames. For example, in a typical smart meter, there are more UL than DL DATA frames. SIFS AP STA Wake SIFS MoreData=0 RspFrm=00 MoreData=1 RspFrm=11 D D MoreData=1 RspFrm=11 MoreData=0 RspFrm=10 SIFS MoreData=0 RspFrm=11 D MoreData=1 RspFrm=00 DD A STA has prior knowledge of the existence of buffered DL DATA, e.g. saw TIM bit in Beacon B July 2012

14. Submission doc.: IEEE 802.11-12/0834r0 Conclusion Speed frame exchange combines uplink and downlink medium access This approach reduces medium access and contention time Fewer frame transactions between AP and STA are needed STA remains awake for less time, and hence achieves power- saving Slide 14Eric Wong, Broadcom July 2012

15. Submission doc.: IEEE 802.11-12/0834r0 Straw Poll 1 Do you support to include the concept of speed frame exchange, and use of More Data field in the TGah specification framework document? Yes No Abstain Slide 15 July 2012 Eric Wong, Broadcom

16. Submission doc.: IEEE 802.11-12/0834r0 Straw Poll 2 Do you support to modify the definition of value (b11) response frame type to indicate the presence of a frame that is not ACK, CTS or BA following current transmission in the TGah specification framework document? Yes No Abstain Slide 16 July 2012 Eric Wong, Broadcom

17. Submission doc.: IEEE 802.11-12/0834r0 References [1] S. Merlin et al., “Low Power Medium Access,” 11-12/0127r1 [2] M. Fischer et al., “Target Wake Time,” 11-12/0823r0 [3]Y. Liu et al., “Early Ack Indication,” 11-12/0119r0 [4]IEEE 802.11 REVmb D12.0 [5] M. Park et al., “Uplink channel access,” 11-12/606r1 Slide 17Eric Wong, Broadcom July 2012